Steerable vehicle truck



Oct. 15, 1940.

A. RONNING STEERABLE VEHICLE TRUCK Filed Dec. 26, 1939 INVENTOR 4D OLPH 'PO/V/V/NG BY MM YW ATTORNEYE 40 invertical cross section. seal rings l9 so'that the interior of the housing 40 Patented Oct. 15,1940 I I 2,217,816

U NITED STATES P orrrcs "2,217,816 r STEERABLE VEHICLE TRUCK Adolph Ronning, Minneapolis, Minn.

Application December 26, 1939, Serial No. 310,941

17 Claims. (Cl. 280-87) This invention relates to improvements in necessary lateral stability. The steering post C steerable supporting units 01' trucks for wheeled is oscillated about its vertical axis by the usual vehicles, particularly of the automotive type, and steering mechanism, which is not here shown but the primary object is to provide novel, efiicient, is described in certain of my copending applica- 5 and practical means for mounting a pair of closely tions hereinbefore identified, and the front ground 5 spaced wheels so that they may be steered about a wheels D are mounted to this post to be angled central vertical axis but so that they will have thereby for steering purposes. These wheelsD are freedom for relative and interdependent up and closely spaced since they are not designed to give down motion to thereby equally distribute load lateral stability and also because they are instresses between the wheels and facilitate steering tended to travel between crop rows when the trac- 10 action over rough or uneven ground surfaces. torisused for row crop work. 7 Such differential action of the wheels furthermore The lower end of the steering post C is flanged reduces the amount of up and down movement at 5 beneath the bearing B for the attachment, imparted to the vehicle as the wheels meet irreguas by screws 6, of the upper flanged end 1 of an larities in the ground surface over which they upright, steerable, mounting member 8, said 15 travel. I flange 5 bearing upwardly against a thrust bear- This application is companion to several of my ing 9 to support the frontal end of the tractor. copending applications, and for a disclosure of The member 8, preferably hollow for lightness and other forms of functionally similar mechanisms strength,is turned forwardly at its lower end i0 attention is invited to my other applications Serial and isintegrally connected with a housing I l. 20- No. 219,369, filed July 15, 1938; Serial No. 242,725 Said housing II is vertically elongated and made and Serial No. 242,726, filed November 28, 1938, up of two complementary sections rigidly secured now Patents Nos. 2,208,599 and 2,208,600 of July together by bolts I2, the rear section being into- 23, 1940; Serial No. 244,019, filed December 5, gral with the member 8 as clearly shown so that 1938, now Patent No. 2,208,601 of July 23, 1940; the housing will turn with this member and the 25 Serial No. 247,608, filed December 24, 1938, now steering post C as the steering mechanism is Patent No. 2,209,093 of July 23, 1940; and Serial manipulated.

No. 250,344 and Serial No. 250,345, filed January The wheels D are mounted on spindles l3 ex- 11, 1939, now Patents Nos. 2,209,094 and 2,209,095 tending rigidly from the rear ends of crank memof July 23, 1940. bers or arms l4 and I5 disposed on opposite sides 30 In the drawing: of the housing II and provided at their forward Fig. 1 is a side elevation of a lower forward porends with stub shafts I6 and 1?, respectively, tion of a tractor equipped with my invention for which extend in parallelism and vertically spaced mounting the front wheels, said wheels being relation into the housing. Said stub shafts enter shown as running over uneven ground, and the the housing through lateral openings formed at 35 near wheel being in greater part broken away to the, parting line between'the respective housing better disclose the structure. sections and are journaled in spaced anti-friction Fig. 2 is a front end elevation of the structure bearings I8, the openingaonev of which is shownshown in Fig. 1, an upper portionbeing shown in Fig. 3, being sealed around the shafts by oil Fig. 3 is an enlarged horizontal section through may be filled with lubricating oil. A removable the housing and showing one wheel mounting plug 20 is provided for this purpose. The spindles crank of my invention. I3 are slightly sloped outwardly togive the de- Fig. 4 isan enlarged Vertical, longitudinal secsired camber to the wheels as indicated in Fig. 2,

tion along the line 4-4 in Fig. 2, only a part of but it should be noted that any relative up and 4* one crank and the housing support'being shown. down movement of the wheels, about the axes of Fig. 5 is a fragmentary cross section taken along the shafts l6 and 11, will notdisturb either this the line 5-5 in Fig 4. camber or the relative angle of the wheels with I Referring to the drawing more particularly, and respect to the upright steering axis, nor will such by reference characters, A represents the frame movement produce any relatively transverse 5c of a tractor in the front end of which is formed a movement as between the wheels such as would vertically axised bearing B for the reception and result in undesirable frictional ground contact. support of a journaled steering post C. At the It should be noted that, although the member 8 rear the tractor is provided with the usual spaced extends forwardly at its lower end, thus disposin 5 traction wheels (not shown) which give the the housing ll forwardly of the vertical axis the post C, the cranks l4 and I 5 both extend rearwardly at their wheel supported ends whereby the wheels operate directly opposite the member 8 and in normal alignment, and in the transverse vertical plane of the steering axis. The wheels will thus steer without resistance greater than usual.

' The inner ends of the stub shafts l6 and I! carry gears or gear segments 22 and 23 respectively, which segments are rigidly affixed to the shafts and operate in meshing engagement within the housing I I. The gear segments are narrower than the interior width of the housing, and the inner walls of the housing, in line with the gears, are grooved out as shown at 24 to clear the teeth of the gears as they turn. The lower end portion of the housing has stops or stop lugs 25 located at opposite points in the groove 24 in position to be engaged by the teeth of the lower gear and so limit the movement of the gears in either direction.

It will be understood that as the weight of the tractor is imposed on the housing II it will be transmitted through the gears 22-43, the stub shafts |6-l'l and cranks l|l5 to the wheels D, all of which parts -will remain substantially stationary while traveling over a smooth surface.

When uneven surface is encountered, as illustrated in Figs. 1 and 2, then the gears 22-23 will function to permit the wheels to assume relative vertical positions, either crank arms l4 and I5 moving upwardly while the other moves downwardly an equal amount, and in a differential manner. The applied weight will, however, be at all times evenly distributed to the wheels.

The relative vertical movements ofthe wheels are limited by engagement of the lower gear 22 with the stops 25, but in all normal usage these; stops will not be reached and the movement is free of all shocks or jars.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is: s

I 1. A steerable vehicle supporting truck comprising a member mounted for oscillation about a generally upright axis, a pair of cranks respectively pivoted at relatively higher and lower levels in the member, and for movement therewith about said axis, ground wheels rotatably mounted on. the cranks, and gear means differentially connecting the cranks and 'operative to cause opposite up and down movements thereof as the truck travels over an irregular surface.

2. A steerable vehicle. supporting truck comprising a member mounted for steering movement about an upright axis, a pair of cranks disposed on opposite sides of the member and pivoted thereto on vertically'spaced axes, ground wheels rotatably secured to the cranks, and means differentially connecting the pivoted ends of the cranks for translating an up movement of either ground wheel to an equal down movement of the other. 4

3. In a vehicle,- a steerable truck supporting one end thereof and comprising a pair of wheel supported cranks mounted for vertical oscillating movements about transversely extending, vertically spaced centers, and for steering movements about a common axis the transverse plane of. which is substantially coincident with a vertical plane through the axis of the wheels, and gear means difierentlally connecting the cranks causing them to oscillate in opposite vertical directions.

4. In a vehicle, a steerable truck supporting one end thereof and comprising a pair of wheel supported cranks mounted for vertical oscillating movements about transverse, vertically spaced centers, and for steering movements about a common substantially vertical axis, and means differentially connecting the cranks causing them to oscillate in opposite vertical directions.

5. A steerable vehicle truck comprising a member mounted for movements about an upright axis for steering purposes, a pair of cranks journaled at one end in the member for movement therewith about said axis, the said cranks being journaled in said member on transversely extended and vertically spaced axes for movements thereabout in ground wheels rotatably secured to the cranks, and means difierentially connecting the journaled ends of the cranks and operative to cause opposite up 'and down movements of the cranks and to cause the imposed vehicle weight to be ,transmitted and distributed equally to the wheels in any relative vertical positions thereof.

6. In a steering truck for vehicles, a mounting member movable about a generally vertical axis, wheel supported members secured to the mounting member, one at each side thereof, for oscillating movements about transversely extended axes disposed in vertically spaced planes, and gear means differentially connectingsaid wheels supported members.

'7. In a\steering truck for vehicles, a mounting 3 member rotatable about a generally upright axis, a pair of wheel supported members connected to the mounting member at opposite sides thereof for oscillating movements about transverse axes spaced one above the other, and means difierentially connecting the wheel supported members. 8. In a steering truck for vehicles, a mounting member movable about a substantially vertical axis, a pair ofwheel supported crank arms carried at opposite sides of the mounting member and pivotally connected thereto upon vertically spaced and substantially parallel axes for oscillation in substantially vertical planes, and means difierentially connecting the arms for translating vertical movement of either into corresponding movement of the other in an opposite direction.

9. In a truck for supporting a vehicle, amounting member, a pair of wheel supported crank arms disposed at opposite sides of the member and pivotally connected thereto uponvertically spaced axes foroscillation thereabout in generally vertical planes at their wheel supported ends, and means differentially connecting the arms causing them to oscillate in opposite directions in their respective vertical planes.

substantially vertical planes,'

10. In a truck for supporting a vehicle, a

mounting member, a pair of wheel supported crank arms disposed at opposite sides of the memher and having journaled connections therewith on respective axes whereby the cranks may move in transversely spaced planes parallel with the direction of travel, said axes disposed one higher than the other, whereby said arms may oscillate in vertical planes at their wheel supported ends, and, gear means differentially connecting the arms.

11. A vehicle supporting device comprising a mounting member, a housing secured thereto, a pair of crank arms pivoted at -one end in the housing on vertically-spaced and parallel axes,

ground wheels rotatably secured to the arms, and a gear train differentially connecting the arms.

12. A vehicle supporting device comprising a housing, a pair of wheel supported crank arms journaled to the housing on vertically spaced substantially horizontal axes, and meshing gear segments on the journaled ends of the arms connecting the arms for difierential vertical swinging movements.

13. A vehiclesupporting device comprising a mounting member, a housing thereon, a pair of wheel supported cranks journaled at their ends through opposite sides of the housing on vertically spaced, substantially horizontal axes for vertical swinging movements thereabout, gears on the journaled ends of the arms within the housing and meshing with each other for differentially connecting the arms, and means limiting the movements of the arms.

14. A vehicle supporting truck comprising a housing, a pair of crank arms journaled at one end through opposite sides of the housing at vertically spaced locations therein and for oscillating movements in substantially vertical planes, ground wheels supporting the arms and movable vertically therewith, gears located within the housing and secured to the respective journaled ends of the arms in meshing engagement for differentially connecting said arms, and stop means in the housing for engaging one gear and limiting oscillating movements of the arms.

15. A vehicle supporting device comprising a housing, a pair of crank arms joumaled through opposite sides of the housing on vertically spaced and substantially horizontal axes for oscillating movements thereabout, ground wheels rotatably secured to the arms, segmentally toothed gears toothed gears located in the housing and secured to the journals of the crank arms in meshing engagement to thereby difierentially connect the said arms, the said housing having inner grooves located in the plane of the gears for giving clearance to the toothed portions thereof, and stops located in said grooves for engaging the toothed portion of one gear and thereby limiting the differential movements of the crank arms. v

1'7. A steerable vehicle truck comprising a mounting member mounted for oscillation about a generally vertical steering axis, the lower end of said member being turned forwardly, a pair of cranks journaled on said lower end of the memher on vertically spaced and horizontally extend- 

